I’d stick with the full render. 
The interstitial is a distinct decision point — “review these duplicates, then choose” — not an inline update to the form. 
Turbo Streams shine for partial page updates (flash messages, replacing a single row), 
but here the entire page content changes to a different layout (centered card vs. the form).

Also practical reasons:

- The “Go back” link navigates to new_person_path with params — a full page load either way
- The “Create anyway” form already uses data: { turbo: false } because it’s a standard POST that should redirect on success
- Adding Turbo Frames would mean wrapping the new form and the interstitial in matching frames, 
plus handling the layout difference — more complexity for no UX gain
- The render approach is the simplest thing that works correctly here.